Point detector latching mechanism



Oct. 20, 1953 H. L. BONE 2,656,457

POINT DETECTOR LATCHING MECHANISM Filed Dec. 30, 1950 4 Sheets-Sheet l 20 21 6812 23 Fig? 2 INVENTOR.

/ Hep ert L. Bone HIS A TTOHNEY' Oct. 20, 1953 H. L. BONE POINT DETECTOR LATCHING MECHANISM 4 Sheets-Sheet 2 Filed D60. 30, 1950 e M NN m m E wws s 3% SN r x .Q%. QW/ a. QQW @N \@m" J P 7 I j QM 8 g 5 I) g H v O 0 j O O 6 0 M swam E J o 0 H I r: mm ak m o o o a n Q o o Q l w w w QR g 6 0 mm Nwmw w N av q 0 o N N 0 31mm mw 0 mm wmo o o QR g 4 m kl 5% o 0 egg 0 awk mw o 3 o Q. Q L BNR .Q\ 0 O O O o fi R H @mm o 0 v A o QR L g s g g a N J .5 gm 7K Wm hi gs a Ii 1! r r I A g JJL HIS ATTORNEY Oct. 20, 1953 BONE 2,656,457

POINT DETECTOR LATCHING MECHANISM Filed D60. 30, 1950 4 Sheets-Sheet 3 Fig: 4.

INVENTOR.

' 111,5" ATTORNEY Oct. 20, 1953 H. BONE 2,656,457

POINT DETECTOR LATCHING MECHANISM Filed Dec. 30, 1950 4 Sheets-Sheet 4 v INVENTOR.

Her Iz LBone HIS A TTORNE'Y Patented Oct. 20, 1953 POINT DETECTOR LATCHING MECHANISM Herbert L. Bone, Forest Hills, Pa., assignor to Westinghouse Air Brake Company, a corporation of Pennsylvania Application December 30, 1950, Serial No. 203,708

6 Claims. 1

My invention relates to railway switch operating apparatus and more particularly to a point detector latching mechanism for a circuit controller forming a part of a railway switch operat ing apparatus.

A switch and lock movement for a railway switch generally comprises power and/or manual means for moving the switch points of the railway switch between their two extreme positions and locking them in the extreme position to which they are moved. Such aparatus further includes a circuit controller operated upon movement of av slide bar for operating indication contacts controlling the signals governing trafiic movements over the switch, together with a point detector mechanism controlled by a point detector bar connected to the switch points to control the operation of the indication contacts should the switch points fail to assume or remain locked in their normal or reverse positions for any reason.

The indication contacts of the circuit controller control the operation of an indication relay which in turn controls the signals governing trafiic movements over the switch. The contacts are so prearranged that upon operation of w the switch and lock movement to move and lock the switch in its extreme normal position, one set of indication contacts will be closed while the other set of indication contacts will be opened,

and upon operation of the switch and lock movement to move and lock the switch in its extreme reverse position, the first set of indication contacts will be opened while the second set of indication contacts will be closed. In the event a switch locked in either of its extreme positions is trailed, the point detector bar connected to the switch points will be moved to open the closed set of indication contacts so that a restrictive signal is set against trafiic movements over the switch.

In certain forms of circuit controllers for switch and lock movements, as shown for example in Letters Patent of the United States No. 1,293,290 granted to William Zabel on February 4, 1919 for Railway Trafiic Controlling Apparatus,

movement in this type of a point detector mechanism.

Latching devices are also incorporated in certain types of circuit controllers for switch and lock movements as shown for example in Letters Patent of the United States No. 2,388,819 issued to me on November 13, 1945 for Railway Switch Operating Apparatus, for holding the point detector mechanism in its actuated position, thereby maintaining the restrictive signal set. A point detector latching mechanism of this type provides a positive control of the indication contacts to set restrictive signals for traffic moves over the switch when the switch is trailed, manual restoration of the mechanism, however, is required to clear the restrictive signal. No provisions are made for releasing the latching mechanism upon operation of the switch from its trailed position toward its opposite extreme position.

An object of my invention is to provide a point detector latching mechanism for a circuit controller of a railway switch operating mechanism which will selectively control the indication contacts of the circuit controller and which will assure by way of signal indication that the position of the point detector bar corresponds with the position of the switch movement.

Another object of my invention is to provide a point detector latching mechanism for holding indication contacts open in the event of a trailed switch, the mechanism being restored to its unlatched position upon operation of the switch operating mechanism toward its opposite extreme position from that in which the latching mechanism was tripped.

A further object of my invention is to provide indexing means for the camshaft supporting the contact operating members of the circuit controller which will insure the proper assembly of the operating members relative to each other and to the position occupied by the switch points so that the indication contacts of the circuit controller are operated in proper sequence.

'According to my invention, the circuit controller indication contacts are operated by contact operating cams mounted on a camshaft oscillated by the reciprocal movement of a slide bar upon operation of the switch movement in reversing the switch points, the camshaft being indexed with reference to the angular displacement thereof so that the eccentricities of eccentric bushings mounted on the camshaft together with indication contact operating cams have a predetermined angular position relative to each other. To insure the correct disposition of the camshaft assembly with respect to the indication contacts, the ends of the camshaft are of different diameters fitting only the proper trunnions provided in the circuit controller.

The eccentric bushings are provided with portions which are eccentric with the camshaft, the eccentric portions of the bushings supporting operating levers which are linked to pivoted point detector levers cooperating with a point detector rod connected to the switch points. The .concentric portions of the eccentric bushings serve to support a U-shaped contact operating member which cooperates by way of driving blocks with slotted connections in the operating levers. The contact operating member is provided with cams which cooperate at times with the indication contacts to open thesame whenthe switch is trailed. The trailing of the switch will, by the movement of the point detector bar and consequent movement of an operating lever, rotate the contact operating member to a position in which a cam thereon will open the closed indica- I tion contacts, the operating member then being held its rotated position by a latching member; Upon the subsequent operation of the switch movement to reverse the switch points after .a trailing move the latching member will be released by the arcuate movement of a cam block fixed to the gear wheel on the camshaft. Should the switch movement again be operated to move the switch back to the position in which it was trailed, and the switch points fail to assume their extreme positions, the contact operating member will again be latched up to hold the indication contacts open. The provision of linkage directly connecting each of the operating levers to their individual point detector lever, and the relative positions of the contact operating cams, insure the selective operation of the indication contacts so that the continued failure of a restrictive signal to clear when the switch is thrown to a certain position will indicate at the remote control point for the switch movement, that a particular switch-pointwas' damaged during the trailing move.

Other objects and characteristic features of my invention will become apparent as the description proceeds.

I shall describe one form of a point detector and latching mechanism embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. l is a plan view of a typical switch layout, the switch being illustrated in its normal position. Fig. 2 is a sectional view of a circuit controller taken substantially along the line II-II of Fig. 3. Fig. 3 is a top plan view of a circuit controller embodying my novel point detector and latching mechanism, portions of which have been broken away for illustrating to better advantage the elements thereof. Fig. 4- is a sectional view taken along the line IV-IV of Fig. 3, illustrating the camshaft assembly. Figs. 5, 6 and 7 are schematic drawings of the essential portions of the point detector mechanism illustrating the operation of the indication contacts by the contact operating cams and the contact operating memher' in various positions of the railway switch. Fig. 8 is an isometric, exploded view of a portion of the camshaft assembly shown in section in Fig. 4', while Fig. 9 is a sectional view taken along the line IXIX of Fig. 3 showing details of the latching mechanism.

Similar reference characters refer to similar parts throughout the several views;

Referring now to Fig. 1 of the drawings; the

normal or reverse positions by means of :a throw rod 1 which is connected to the usual basket 8 fixed to the head rod. When the switch A occupies its normal position as illustrated in Fig.

l, themovable rail 2 engages the fixed rail 1 while the movable rail 2a is spaced from the fixed rail lo. When the switch A is in its reverse position, the movable rail 2a engages the fixed rail Ia while the movable rail 2 is spaced from the fixed rail 1.

Secured to the elongated crossties 4 adjacent the outer side of the fixed rail I is a switch and lock movement 13 similar to the movement illustrated and described in Letters Patent of the United States No. 2,388,819 granted to me on November 13, .1945, for Railway Switch Operating Apparatus. The switch and lock movement 58 comprises three enclosures 9, l0 and H housing a drive motor (not shown), a reduction gearing and selector mechanism, not shown here but tully described and illustrated in my copending application Serial No. 203,799, filed on December 30, 1-956, for Railway Switch Operating Mechanism, and a circuit controller 42 (Fig. 3) respectively. Journaled in a suitable bearing of the enclosure I!) are two concentric shafts (not shown) having fixed thereto a hand-throw lever 13 and aselector lever 14. A connecting rod 15 and .a. point detector connecting rod Hia are fixed by suitable means to the front rod 5 and pass beneath the fixed rail Securedto the end of the detector connecting rod is a point detector bar It slidably received within the circuit controller enclosure. Fixed to the end of the connecting rod 15 and received within the circuit controller enclosure .H are two locking bars H and 10 formed with notches in their upper and lower edges, only the lower edge notches I 9 being illustrated in Fig. 2. The notches are engaged by a locking dog 28 forming a part of a lock box 21, when the switch A is in its normal position and properly locked. A second locking dog -22 is provided on the lock box for engaging the upper notches of the locking bars when the switch A is in its reverse position.

Under normal operating conditions, the switch A will be moved to its normal and reverse positions upon operation of the drive motor of the switch and lock movement B. The selector and hand-throw levers provide an overriding manual control of the switch and lock movement. The selector lever 14 when moved from its mo tor position illustrated in Fig. l to its manual position operates a clutch mechanism within the enclosure Ill to disengage the drive motor of the switch and lock movement, at the same time engaging the manual diive for the movement. Operation of the drive motor with the selector lever in its motor position, or movement of the hand-throw lever [3 from one extreme position to the other when the selector lever is in its manual position will operate a switch operating crank (not shown) which cooperates with the throw rod 7 to move the switch points 2 and 2a to their normal and reverse positions. The switch operating crank also cooperates with a slide bar 23 (Fig. 2) to which the lock .box 2! is fixed.

The lock box 2| is provided at its right-hand end with a rack 24, the teeth of which mesh with the teeth of a pinion suitably mounted on a frame 26 in the enclosure II. The rack 24 and pinion 25 are shown in their extreme normal positions, the pinion 25 having been rotated in a counterclockwise direction by the movement of the lock box 2| and rack 24 during movement of the switch points to their normal positions as illustrated in Fig. 1. Reversal of the switch points by the operation of the switch and lock movement B will cause the slide bar 23 to move from right to left, the rack 24 rotating the pinion in a clockwise direction. The movement of the lock box 2| will withdraw the locking dog 20 from the lower notches 19 of the lockin bars I! and i8 permitting movement of the locking bars in response to the reversal of the switch points, the locking dog 22 entering the upper notches of the locking bars at the end of the movement of the switch points to lock the switch points in their reverse position.

The point detector bar I6 is of circular crosssection and formed with an elongated peripheral notch 27 in that portion of the rod within the circuit controller enclosure I l. The point detector bar is adapted to coact with the elements of the circuit controller l2 which will now be described.

The circuit controller 12 is mounted on the supporting frame 26 in the enclosure l I and comprises a horizontal camshaft 2t journaled in aligned trunnions 29a and 2% provided in the frame 26 (Figs. 2 and 3). The camshaft is of square cross-section except for the ends which are threaded as at 30 and rounded as at Ma and 3| 1), the rounded end am journaled in the trunnion 29a. being of smaller diameter than the rounded end 3th. For purposes hereinafter appearing, the camshaft 23 is further characterized by the removal of two portions of the corner of the square shaft as at 28c. and 28b in Fig. 8. The camshaft 28 is adapted to be oscillated in response to the longitudinal movements of the lock box 2| (Fig. 2) by a gear wheel 32 fixed on the camshaft, the gear wheel meshing with the teeth of a pinion gear 25 journaled in the frame 26. I

Mounted on the camshaft 23, on opposite sides of the gear wheel 32 are a plurality of insulating bushings 33w-33d. Each of the bushings is provided with a square opening for slidably receiving the camshaft 28, each bushin comprising a radial web portion (Fig. 4) terminating in a tapered peripheral flange. Metal contact segr ments 34a 34d in the form of ring segments, each formed with a tapered bore, are carried by the tapered peripheral flanges of the insulating bushings 33a33d, respectively. The outer tapered peripheral flanges of the bushings and the tapered bore surfaces of the contact segments are serrated (not illustrated) so that the contact segments may be secured to said bush- The contact fingers 35a--35d and Tic-31d together with the contact segments 34a -34d may be used to control the circuits of the switch and lock movement motor or for any other desired purpose. For a detailed description of the operation of the contact segments and the contact fingers, reference may be made to my aforesaid Letters Patent of the United States No. 2,388,819.

Secured to the terminal block 38 in a suitable manner are two pairs of contact fingers 40a. and 401), each pair of contact fingers being interconnected for simultaneous movement by insulating bridges M and 42, respectively. The contact fingers 40a and 4% are biased by their own resilience in a downward direction to engage the lower stationary contacts 43a. and 43b, respectively, fixed to the terminal block 38, but are adapted to be at times moved upwardly by means of a point detector mechanism, which I shall now describe, to upper positions in which they engage an upper stationary contact 44 secured to said terminal block. The contacts 49a 43a and deb-e3?) when closed complete an energizing circuit for an indication relay (not shown), while the contacts Mia-44 and 400-44 when closed, shunt the indication relay in the manner illustrated and described in Letters Patent of the United States No. 1,293,290 granted to William Zabel on February 4, 1919 for Railway Traffic Controlling Apparatus.

Referring to Figs. 4 and 8 of the drawings, the gear wheel 32 which drives the camshaft 28 is formed with oppositely disposed hubs 32a and 32b, and mounted on the camshaft between the hub 32a and the insulating bushing 33b is a washer 45c and a bushing 46a. A washer 45b and bushing 4612 are similarly mounted on the camshaft 28 between the hub 32?) and the insulating bushing 330. The bushings 46a and 46?) are formed with portions 41a and 411), respectively, which are eccentric with respect to the camshaft 28, and with other portions 48a and 48b, respectively, which are concentric with respect to the camshaft, the concentric portions 48a and 48b being disposed toward the adjacent hubs 32a and 3217, respectively. The hubs 32a and 32b of the gear wheel carry contact operating cams Mia and 4922, respectively, which are connected to the gear wheel to rotate therewith in the manner hereinafter described. The cam 49a is provided in its periphery with an arcuate notch 55, (Fig. 5) and is adapted when rotated to actuate the contact fingers Mia through the medium of a roller 5| attached to the insulating bridge 45. The cam 49b is similarly provided with an arcuate notch 50b, and is adapted when rotated to actuate the contact fingers 4th through the medium of a roller 52 fixed to the underside of the insulating bridge 42. The parts are so proportioned that when either notch is opposite its associated roller, the associated contact fingers are free to move to their lowermost positions, but when the notches are not opposite their respective rollers, the associated fingers will be lifted into engagement with the contact member 44. The contact operating of their respective cams while the switch A moved from one extreme position to its other extreme position (Fig. 6), but the contact fingers 49a will assume their lower positions when the switch A is in its extreme normal position and the roller 5| is within the notch 53a (Fig. 5) ,and

the contact fingers 48-12 will assume their lower positions when the switch A is in its extreme reverse position and the roller 52 is within the notch 501), as will hereinafter be more fully described.

The means for operatively connecting the contact operating cams 49a and 4% with the gear wheel 32 comprises a driving pin 53a (Figs. 4 and 8) which projects from the side of the gear wheel 32 for cooperating with one or the other of two radial slots 54a and 55a formed in the hub of the cam 49a, and a driving pin 53b which projects from the opposite side of gear wheel 32 for cooperation with one of the two radial slots 54?) and 55b formed in the hub of the contact operating cam 49b. The spacing between the slots 54a and 55a is such, and the parts are so arranged that, when the pin 53a is within the slots 54a, the notch 50a in the cam 49a will align with the roller when and only when the switch A occupies its extreme normal position, but when the pin 53a is within the slot 55a, the notch a in the cam 4911 will then align with the roller 5| when and only when the switch A is in its extreme reverse position. Similarly, the spacing between the slots 54b and 55b in cam 49!; is such that when the driving pin 53b is within the slot 5417, the notch 50b in cam 49b will align with the roller 52 when and only when the switch A is in its extreme normal position, but when the driving pin 53b is within the slot 551), the notch 50b of the cam 49b will align with the roller 52 when and only when the switch A is in its extreme reverse position. The contact operating cams 49a and 49?) are usually mounted on the hubs in such positions that the notch in one cam will align with its associated roller in one extreme position of the switch and the notch in the other cam will align with its associated roller in the other extreme position of the switch.

Since the camshaft 28 is square, it would be possible to mount the gear wheel 32 thereon in any one of four positions. In order that the gear wheel 32 and the contact operating cams 49a and 49b are assembled in proper relationship with the eccentric bushings 46a and 462), the corners of the camshaft are removed at 28a and 28b as described, and the gear wheel 32 provided with a pin 56 passing through the hub 32b (Fig. 8) to engage the camshaft portion 28b, while the eccentric bushings 46a and 452) are similarly provided with pins 51 which pass through the eccentric portions thereof and engage the camshaft portions 28a and 282), respectively. In this way the proper assembly of the parts on the camshaft 28 is insured. Since the ends 31a and 3lb of the camshaft are of different diameters and will only fit the proper trunnions 29a and 29?), respectively, the complete camshaft assembly must be installed in the circuit controller with the contact operating cams and contact segments in proper alignment for operating their respective contact fingers.

In order to enable the switch operating apparatus to be used in either a right-hand or a lefthand installation, it is desirable to be able to readily change the contact operating cams 49a and 492; from the positions in which the associated driving pins 53a and 53b extend into the slots 54a and 55b, respectively, to the positions in which they extend into the other slots 55a and 54?), respectively, and for this purpose the cams 49a and 4% are provided at the side opposite to that in which the slots are formed with counterbores 58a and 5822, respectively. These counterbores are slightly larger in diameter than the adjacent washers 45a and D and the parts are so proportioned that when it is desired to rotate a cam from the position in which the associated pin 53a or 5312 enters the one slot in the cam to that in which it enters the other slot this can be done by merely sliding the cam outwardly along the associated hub of the gear wheel 32 far enough to disengage the pin from the slot, rotate the cam until the other slot aligns with the pin, and then move the cam inwardly alon the hub to the position in which the pin enters the desired slot. The cams are held in the position in which the associated pin is within the desired slot by means 01 coil springs 59a and 59b disposed in the counterbores. As here illustrated the cam 49a occupies the relative position on the hub 32a in which the associated pin 53a is within the slot 54a, while the cam 49b occupies the relative position on the hub 32b in which the associated pin 53b is within the slot 551). With this arrangement, insofar as the control of the contact fingers loaf-40b by the cams 49a and 49b is concerned, the contact fingers 40a will be held in the positions in which the contacts Illa-43a are open and the contacts Illa-44 are closed except when the slide bar 23 occupies the extreme normal position, and the contact fingers 40b will be held in the positions in which the contacts lob-43b are open and the contacts 40b-44 are closed at all times except when the slide bar 23 occupies the extreme reverse position.

The contact fingers 40a and 40b are further controlled in accordance with the positions of the switch points through the medium of two cams 60a and 60b (Figs. 5 to 8) which are formed on the arms Bio and Bib of a U-shaped contact operating member 6|, said cams cooperating respectively with the rollers 5| and 52 at one side of the cams 49a and 49b. The arms 6 la and Bib are journaled on the portions 48a and 48b of the bushings 48a and 46b which are concentric with respect to the camshaft 28. The U-shaped contact operating member 6| is further provided with arms 62a and 62b spaced from the inner sides of the arms 61a and Bib. Rotatably mounted in the ends of the arms 62a. and 62b and in the arms Bio and Gib are pins 63a and 631), respectively, having fixed thereto adiacent the outer sides of the arms Bio and Gib the driving blocks 54a and 64b, respectively; snap rings 65 holding said pins in place. For purposes hereinafter appearing the U-shaped contact operating member 6| is provided between the arms 62a and 62b with a bevelled surface Blc having a slot Sid therein, the bevelled surface terminating at its upper end in a flat abutment surface Sic (Fig. 8).

The driving blocks are slidably received in the projecting jaws 56a and 66b of two operating levers 81a and 61b, respectively. The levers 56a. and 66b are journaled on the portions 41a and 41b of the bushings 48a and 46b eccentric with respect to the camshaft 28 and are further provided with depending anns 68a and 68b which are pivotally connected to adjustable operating rods 69a and 69b, respectively. The free ends of the operating rods 69a and 69b, in turn, are connected by eye rods Illa and 10b with the inner ends of two horizontally disposed point detector levers Ha and lib as by pins 12a and 12b. The point detector levers are pivotally supported on pivot pins 13a and 13b mounted in suitable supports formed in the enclosure l i.

The point detector levers Ha and 1 lb are provided at their outer ends with rollers 14a and .9. 745, respectively. Tension springs a and 15b are connected at one end to the point detector levers Ha and 12b, respectively, and at the other end to lugs [50 on the frame 26, and constantly bias the point detector levers toward positions in which the associated roller 14 is adjacent to but does not engage point detector bar I6 slidably mounted in the circuit controller enclosure II. The point detector bar notch 21 aligns with the roller 14b when and only when the switch 'j points occupy their proper normal positions and with the roller 14a when and only when the switch points occupy their proper reverse positions.

The bushings 46a. and 46b are provided with square holes to fit the camshaft 28 and with the pins '51, so that the bushings will be mounted on the camshaft in their proper positions as heretofore described. The pins 51 of the bushings are so placed with respect to the eccentricportions 41a and 411) that when the bushings are properly placed on the camshaft 28 so that the bushing pins 51 register in the corresponding cut-off portions 28a and 28b of the camshaft, a line extending from the eccentric center to the center of the shaft is spaced 30 from the nearest diagonal line interconnecting the ends of the square hole. The bushings are assembled on the shaft in such relative positions and the parts are so proportioned that when the notch 21 in the point detector bar is is in alignment with either roller 14, the spring 15 connected with that point detector lever H to which such roller is attached will rotate this lever to the position in which the roller enters the notch. Both springs 15a and 15b will act through their associated point detector levers Ha and Nb, the associated operating rods 69a and 6%, the operating levers 61a and 61b, and driving blocks 64a and 64b, respectively, to rotate the contact operating member 6| to the position in which the cams 60a and 60b will be out of the path of movement of the rollers 5| and 52, so that insofar as the control of contact fingers 40a and 40b by the point detector rod [6 is concerned these fingers are free to move to their lowermost positions. The parts are still further so proportioned that if either roller is forced out of the notch in the point detector bar when the switch is locked in the extreme position in which the notch aligns with such roller, as by a train trailing the switch, the resulting movement of the associated point detector lever will act through the associated operating rod 69, operating lever 58, and driving block 64 to rotate the contact operating member 6| in a counterclockwise direction, as viewed in Fig. 2, to such a. position that the cams 60a and 601) will then engage the rollers 5| and 52 and will thus move the contact fingers to their upper positions in which they engage the contact member 44. When the switch is moved from either extreme position to the other by the operating apparatus, the resulting movement of the camshaft 28 which takes place during the locking stroke of the slide bar 23 will act through the eccentric portions 41:; and 41b of the bushings 46a and 46b and associated linkages to rotate the point detector levers to positions in which both rollers are clear to the point detector bar, and these rollers will be subsequently retained out of engagement with the point detector bar until the switch becomes locked in its reverse position It will be apparent that when the switch occupies its normal position in which it is shown in Fig. l, and locked in this positon by the lock box 2|, the notch 50a in the contact operating cam 49a will align with the roller 5|, and the cam 60a will be out of alignment with the roller 5| as shown in Fig. 5, and under these conditions the fingers 48a will assume their lowermost positions in which the contacts Mar-Alia are closed and the contacts 40a-44 are open. Likewise, when the switch occupies its reverse position, and is locked in this position by the lock box 2|, the notch 56b in the cam 49!) will align with the roller 52 and the cam 60?) will be out of alignment with this roller, and the fingers 40b will therefore assume their lowermost positions in which the contacts 40b-43b are closed and the contacts deb-44 are open. When, however, the switch is being moved from one extreme position to the other, the notch 50a in the cam 49a will be out of alignment with the roller 5| and the notch 59b in the cam segment 4% will also be out of alignment; with the roller 52 (Fig. '6), so that under these conditions both sets of contact fingers 40a and 4% will be moved to their raised positions in which the contacts Mia-43a and lflb43b are open and the contacts Mia-44 and 46b44 are closed.

For purposes hereinafter appearing, a bracket 16 is fixed to the top surface of the terminal block 36 (Fig. 9), the bracket comprising a horizontal arm-16a provided with an upstanding spring lug 16b, the arm being bifurcated at the inner end and formed with enlarged rounded portions and terminating in dependent arms 16d. Pivoted to the bracket 16 between the inner ends as by a pin 11 supported in the portions 160, is a latching member 18. The latching member comprises a substantially horizontal arm 18a overlying the gear Wheel 32, a dependent arm 18b, and an upstanding spring lug in alignment with the spring lug 16b. A coil spring 19 interposed between the spring lugs 16b and 180 biases the latching member 18 in a counterclockwise direction about its pivot so that the dependent arm 18b enters the slot Bld of the contact operating member -6l.

It should be noted that while the switch A is being moved from either extreme position to the other, the tension springs 15a and 15b constantly exert a force on the contact operating member 6| which is considerably greater than that due to any friction which may exist between the operating levers 61a and 61b and the associated eccentric portions of the bushings 46a and 46b. tending to rotate the contact operating member 6| in a counterclockwise direction, as viewed in Fig. 2, and that as a result the contact operating member 6| remains stationary in the position in which the lower edges 16a of the dependent arms 16d of the bracket are engaged by the abutment surface Gle of the contact operating member during reversal of the switch. Consequently, the

rotation of the eccentric bushings 46a and 4622 resulting from the unlocking and locking strokes of the switch operating crank causes the operating levers 61a and 61b to traverse an orbit which slides the driving blocks 64a and 64b longitudinally in the jaws 66a and 66b and which acts during the unlocking stroke of the switch operating crank to move both rollers 14a and 14b away from the point detector bar [6 to positions in which both rollers are completely clear of the bar, and during the subsequent locking stroke to move both rollers toward the detector bar to such positions that at the end of the locking stroke the roller which was initially out of the notch in the detector bar will have entered this notch.

The contacts MCI- 33a and 4522-43?) of the circuit controller are usually referred to as the indication contacts, while contacts Mia-44 and 40b44 are referred to as the shunting contacts. The function of the contacts is to so control signals governing traffic over the switch connected to the switch operating apparatus that these signals will indicate stop unless the switch points occupy their proper extreme positions relative to the stock rails and are locked in these positions. When, by error, the switch is trailed through, the switch points are displaced at the top an amount which would easily operate the circuit controller if the connection of the point detector bar with the switch points could be made at the top of the points. However, for clearance reasons, it is necessary to connect the detector bar to the switch points some distance below the top of the points where, due to the rolling of the points during the trailing, the amount of the movement may not be more than one half of that occurring at the top; and furthermore, after a train ha trailed through the switch, the points will usually spring back toward their original positions a certain amount. As a result, the final displacement of the point detector bar may be very little, if any, more than the displacement which would correspond to a maximum permissible opening of the closed switch point (which is the setting at which the circuit controller would be adjusted to operate the indication contacts), while the opening of the closed point at the top might be sufficient to be extremely dangerous for subsequent high speed train movements. In order to insure that this dangerous condition will be detected, I provide the circuit controller I2 with the latching member 18 for holding the indication contacts in their operated positions after they are once operated by displacement of the switch points.

When the contact operating member 6! occupies its normal position in which it is shown in Fig. 2, the dependent arm 18b of the latching member is held in slot 61d of the contact operating member by means of the spring 19. When, however, the contact operating member is moved in a clockwise direction to its contact operating position as by a train trailing the switch, the spring 19 then rotates the latching member 18 in a counterclockwise direction so that the lower edge 18d of the dependent arm of the latching member engages the top surface Sle of the contact operating member 6| (Fig. 7). When in this position, the lower end of the latching member prevents the contact operating member 6| from returning to its normal position in which it is shown in Fig. 2. Once the indication contacts are operated by operation of the point detector bar IE, it will not be possible for the contact fingers ilm or $01), as the case may be, to return to their lowermost positions until the latching finger is restored to its normal position.

From the foregoing description of the latching member 13 and its operation, it will be readily apparent that the contacts 40a43a and 40b43b may be released by lifting the latching member arm 18a so that the latching, member is rotated in a clockwise direction. The clockwise rotation of the latching member will disengage the abutting edge 18d of the latching member and the upper surface 6| 6 of the contact operating member so that the springs 15a and 75b may then rotate the contact operating member 6| in a counterclockwise direction to a position where the top surface ile thereof! again abuts the lower edges Hie of the depend ing arms lid of the bracket 75.

Means are provided for lifting the latching member from its latching position upon operation of the switch and lock movement B to move the switch from the position in which it was trailed to its opposite extreme position. To this end the gear wheel is mutilated to the extent that one or more of the teeth are removed and a cam block is fixed into the space by a screw 8|.

Rotation of the gear wheel I2 in a counterclockwise direction upon movement of the lock box 2| from its extreme normal position to its extreme reverse position, will move the cam block 89 in an arcuate path underneath the overlying arms 18a of the latching member, thereby lifting said arm and rotating the latching member in a clockwise direction. The clock wise rotation of the latching member will release the contact operating member 6| so that tension springs 75 may again return the con tact operating member to its unlatched position in which it engages the stop means 16c of the bracket. Should the latching member 76 be held in its latching position when the switch points are in their extreme reverse positions and trailed, the clockwise rotation of the gear wheel 32 by the movement of the slide bar 23 to its extreme normal position upon operation of the switch and lock movement, will lift the latching member 18 to release the contact operating member in the manner described.

It will be appreciated from the foregoing description that under normal operating conditions of the circuit controller, i. e., when the latching member 18 is in its unlatched position, that sufficient clearance is provided between the arm 18a of the latching member and the gear wheel 32 to permit the passage of the block 80 therethrough without engaging the latching member arm.

Should the self-restoring latch feature of the latching mechanism described be undesirable for any reason, the cam block 80 may easily be removed from the gear wheel 32 upon removal of the screw 81. It will be apparent that with the cam block 80 removed, the mutilated portion of the gear wheel will not interfere with the proper operation of the circuit controller. Should it prove desirable not to have the point detector latch up after a trailing move, the latching member 18 may be readily removed by removal of the pin 1'! and the biasing spring 19. The indication contacts 40a-43a are usually referred to as the normal indication contacts, the contacts 40a43a being closed when the switch A is in its normal position illustrated in Fig. l. The indication contacts 40b-43 are referred to as the reverse indication contacts, the contacts Nib-43b being closed when the switch A is in its reverse position. With the switch A in its normal position as illustrated, the normal indication contacts Mia-43a will be closed and the shunting contacts 400-44 open, while the reverse indication contacts 40b43b will be open and the shunting contacts 4Ub closed. Should the switch A be trailed while in its normal position, the movement of the point detector bar 16 will force the roller 1412 out of the point detector bar notch 21, rotating the point detector lever Hb in a counterclockwise direction, thereby rotating the contact operating member Si in a clockwise direction as hereinbefore described. The reverse indication contacts lob-43b being open, will not be affected by the clockwise rotation of the cam 60b of the contact operating member. The normal indication contacts Mia-43a are closed however due to the registry of the roller with the cam notch 50a, so that the clockwise rotation of the cam 50a on the operating member will lift the roller 5| to open the indication contacts 40a43 and close the shunting contacts Alla-44. Thus, when the switch A is in its normal position, the point detector mechanism described will open the normal indication contacts in the event the switch is trailed in that position. With the switch A in its reverse position and trailed, the cam 60b of the operating member 6| will open the reverse indication contacts 40b-43b and close the shunting contacts 4012-44 in a similar manner. It follows, therefore, that the operation of the switch and lock movement after the switch A has been trailed to reverse the switch points, the failure of a particular set of indication contacts to close and clear the signals controlling traffic over the switch A, will indicate which of the two switch points has been damaged.

In the event the point detector bar is disconnected or broken off but with the point detector bar in its normal position as illustrated in Figs. 2 and 5, the reversal of the switch points to their reverse positions will rotate the camshaft 28 in a counterclockwise direction (Fig. 2), the contact operating cam 49a opening the normal indication contacts 40a-43a and closing the shunting contacts Mia-44. The notch 50b of the contact operating cam will be rotated to a position where the roller 52 will register therewith. However, due to the point detector lever roller 14a riding over the periphery of the point detector bar I6, the contact operating member 6| will be rotated in a clockwise direction so that cam 60b thereon lifts the roller 52 to hold the reverse indication contacts Nib-43b open and the shunting contacts dob-M closed. Thus both pairs of indication contacts will be held open, while the shunting contacts are closed. A return of the switch points to their normal position will permit the normal indication contacts Mia-43 to close and the shunting contacts 40a44 to open, the reverse indication contacts dub-43 remaining open and the shunting contacts lb-44 closed. Should the point detector bar is be disconnected when the switch A is in its reverse position, a reversal of the switch points will open all indication contacts and close all shunting contacts in a similar manner, the return of the switch points to their reverse positions permitting the indication contacts 40b-43b to close.

Thus in operating the switch and lock movement B from a remote point the continued failure of the signals to clear when the switch A is moved into an extreme position will indicate that the switch and lock movement is not functioning properly, and a maintainer will then be sent out to check on the switch damage.

An advantage of a point detector and latching mechanism embodying my invention is in the selective operation of the indication contacts of the circuit controller so that the particular switch point which does not assume its proper extreme position adjacent the stock rail may be ascertained at the point of control for the switch and lock movement. The self-restoring latching arrangement operative upon movement of the switch points from their trailed position toward their opposite extreme position permits a check to be made from the remote control point of the condition of the switch points, the failure of the signals governing trafiic movements over the switch to clear being indicative of the malfunctioning of the switch and lock movement. A further advantage of my point detector and latching mechanism is in the indexed camshaft assembly provided, the severed corners of the camshaft and the pins provided in the gear wheel and in the eccentric bushings insuring the proper angular relationship of the indication contact operating cams with each other, and with the eccentric portions of the bushings which support the operating levers and the contact operating member. The further provision of trunnions of different diameters for the ends of the camshaft and the provision of different sized ends on the camshaft make pos-. sible the preassembly of the parts on the camshaft with the assurance that the contact making elements and contact operating members thereon will be aligned with and operate the proper contacts of the circuit controller in proper sequence.

Although I have herein shown and described only one form of a point detector and latching mechanism embodying my invention, it will be understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1, In a circuit controller of a railway switch operating apparatus having a slide bar movable to two extreme positions corresponding to the two extreme positions of the switch points, the combination of two contacts, a shaft having reference surfaces thereon and two dissimilar ends, two dissimilar bearing supports for the ends of, said shafts, each bearing support being adapted to receive a particular end of said shaft; a gear fixed on said shaft and rotated upon movement of said slide bar, means on said gear for engaging one of said reference surfaces on said shaft only when said gear is fixed to said shaft in the angular position predetermined by one of said reference surfaces, a contact operating member for each contact on said shaft and fixed in predetermined angular positions with respect to said gear so that upon movement of said slide bar from one extreme position to the other extreme position to rotate said shaft, said operating members will close the first of said contacts and open the second of said contacts when said slide bar is in one extreme position and close the second of said contacts and open the first of said contacts when said slide bar is in its other extreme position; eccentric bushings on said shaft, operating levers journalled on said bushings, a point detector mechanism connected to said switch points and said operating levers, a third contact operating member rotatable on said shaft and operatively connected to said operating levers, means on said bushings for engaging said reference surfaces only when the eccentricities of said bushings are in a predetermined angular position with respect 7 to each other and said gear so that when said point detector mechanism is operated by a, displaced switch point said third contact operating member will be moved to open the closed contact, a latch member biased toward a latching position cooperating with aid third contact operating member to hold said member in its contact 15 opening position, and cam means rotatable-with said shaft for movingsaid latch member to its unlatching position to release said third member when saidslide baris moved from oneextreme position toward its other extreme position.

2. In combination with: railway switch operating apparatus of thetype having a slide bar for looking theswitchpoints in their two extreme positions, a shaft, a gear'on" said aha-fit rotated upon movement of said slide bar; a first and'a secondpoint detector leverea-ch provided: with a roller, apointd'etector bar securedlto theswit'ch pointsand movable-thereby. to corresponding first and secondextremepositiona said point detector bar: being provided with a notchwhich; aligns with .said first point detector leverroller when and onlyi when the point detectorbar-isinits first'extremeposit-ion andwiththesecond:pointdetector lever roller whenthe point-vdeteotor-bar is inits second extreme position, twoeccentric bushings onlsaidshaft, two operating leverscjournaledon. saidremn ic: bushings and roperatively. connect;- edtosaid,pointidetector leversrespectively. aafirstandasecond contactoperating camronsaidsha-ftand rotatable therewith, a contact operating member journaledon. said, shaft and. provided with a, third and afourth cam, saidv contact operating member beingoperatively connectedto said operating levers, a .firstic-ontactcontrolled by said firsta'nd third cams anda second contact controlled bysaidsecondrand fourth cams; indexing means to alignthe eccentricities of saidbushings and saidcontactoperating cams in a predetermined angular relation with each otherandsaid shaft ,to operate said first and second contacts in .propersequence, said means comprising reference surfaces, on said shaft, pinsin said bushings and saidgear registering with said reference surfaces, turned ends on saidshaft of different diameters, and fixed trjunnion's accommodating only the proper ends of the shaft; so thatwhen and only when said point detector bar is in its first extreme position andsaid first point detector lever roller is in said'notch' willfsaid first'cam permit said first'contactto close, and when and only when saidpoint detector bar is in its second extreme position 7 and said, second point detector lever. roller is'in-said notch will'said' se'condicam permit said'secondcontactto close, the movement of said point detector bar from its first extreme position forcing said first point detector lever 'rolL. er outof said notch to rotate the associated operating lever thereby rotating said contact operating member.- said 'third 'cam opening said first contact, the movement of said point detector bar from its'second' extreme position forcing said second point-detector lever roller out of sitidnotch to rotatethe-associated operating lever thereby rotating said contact operating member, said fourth cam opening said second contact.

3:; In* combination with railway switch operating-apparatus of the type having a slide bar forlocki-ngthe switch points'in their two extreme. positionsa shaft operatively connectedwith said slide'bar for rotation thereby, a first'and a sec ond-pointdetector lever each provided'with a roller, apoint detector bar secured to theswitch points and. movable thereby to corresponding first and second extreme positions, said point detector. bar. being providedv with a notch which. aligns with; said first point detector lever.rollerwwhenand; onlywhen the point detector bar is ingitsafirstn extreme position and. with the-second; point deetector lever roller ,when the point .detcctonlbar .isin, its second extreme position; two a eccentricbushings on said shaiLtwo operating leVersd'oui' naled on said eccentric bushings and operatively connected to said: point detector levers respec tively, a first and a second contact operating can! on said shaft and rotatable therewith, a contact operating member journaled on said shaft and provided with a third and a fourth canr, said contact operating member'being operativel'y con nected to said operating levers, afirst contact controlled by said first and third cams and a second contact controlled by said secondand fourth cams; indexing means on said sh-af'fiand said eccentric bushings to align thee'ccentricltics of 'saidbushings and said" contact operating cams in a predetermined angular relation with each other and said'shaft to operate:said-first and sec-- ond contacts in proper sequence so that when and only when said" point detector bar isin its first extremeposition and said first point detector lever roller is in said'notch will said first cam pew mit said first contact to close, and when and'onl y' when said point'detector bar is in its second -p'osi tion andsaid second point detector lever roller is in said notch willsaid second'cam p'ermitsald' second contact to close; movement ofsaidpoint detector bar from its first extreme essimism ing said first point detectorlever rollerout of said notch to rotate the associated operating 16-- ver thereby rotating saidcontact operating mem-- her, said third cam on said member openingsaid' first contact; movement of said point detector bar from its second extreme positionforcing said second point detector. lever roller out of said notch to rotate the associated operating lever thereby rotating said contact operating member, said fourth cam on said'memo'er' opening said second contact; a latch'member cooperating'with said contact operating member to hold-sai'd contact operating member in the position'to"-whicli it is rotated'by the rotation of said'op'erating le'- vers by said point'detector levers, anda-camrm tatablc with said shaft to move said latch' membcr toward its unlatchi-ng' position when said slide bar is moved from one extreme positiontoward' its otherextreme position to release said contact operating member.

4. In railway switch operating apparatus' of the'type having a slideb'ar for-locking the switch points in their two extreme positions; a shaft, a gear fixed to said shaft and rotated-upon movc ment ofsaid slide bar; afi'rst and a second-"pointdetector lever each provided'with a roller, a-poiht detector bar secured to the switch points and" movable thereby to correspondingfiist and second extreme positions, said point detector b'ar being provided with a notch which-aligns witlr'said' first point detector lever roller when andonly when the point detector b'ar isin'its firstextreme position and withthe'second-point detector lever roller when the point'detector bar isir'r-its second extreme position, two eccentric "bushings controlled by said first and third cams and a second contact controlled. .by said. second and fourth cams; the combination of indexingm'ea'ns on said shaft andon said eccentric bushingstsaid first and second contact operating-cams and-gen to align the eccentricities of said bushings and said contact operating cams in a predetermined angular relation with each other and said shaft so that when and only when said point detector bar is in its first extreme position and said first point detector lever roller is in said notch will said first cam permit said first contact to close, and when and only when said point detector bar is in its second position and said second point detector lever roller is in said notch will said second cam permit said second contact to close; movement of said point detector bar from its first extreme position forcing said first point detector lever roller out of said notch to rotate the associated operating lever thereby rotating said contact operating member, said third cam on said member opening said first contact; movement of said point detector bar from its second extreme position forcing said second point detector lever roller out of said notch to rotate the associated operating lever thereby rotating said contact operating member, said fourth cam on said member opening said second contact; a latch member biased toward a latching position and cooperating with said contact operating member to hold said contact operating member in the position to which it is rotated by the rotation of said operating levers by said point detector levers, and a cam fixed to said gear engaging said latch member in its latching position to move said latch member toward its unlatching position when said slide bar is moved from one extreme position toward its other extreme position to release said contact operating member.

5. In a circuit controller of a railway switch operating apparatus having a slide bar movable to two extreme positions corresponding to the two extreme positions of the switch points, the combination of two contacts, a shaft rotated upon movement of said slide bar, a contact operating member for each contact on said shaft and fixed in predetermined angular positions with respect to said shaft so that upon movement of said slide bar from one extreme position to the other extreme position to rotate said shaft said operating members will close the first of said contacts and open the second of said contacts when said slide bar is in one extreme position and close the second of said contacts and open the first of said contacts when said slide bar is in its other extreme position; a point detector mechanism connected to said switch points, a third contact operating member rotatable on said shaft and operatively connected to said point detector mechanism so that when said point detector mechanism is operated by a dis-- placed switch point said third contact operating member will be moved to open the closed contact; a latch member biased toward a latching position and cooperating with said third contact opcrating member to hold said member in its contact opening position, and cam means rotatable with said shaft for moving said latch member to its unlatching position to release said third member when said slide bar is moved from one extreme position toward its other extreme position.

6. In a circuit controller of a railway switch operating apparatus having a slide bar movable to two extreme positions corresponding to the two extreme positions of the switch points, the combination of two contacts, a shaft, a gear fixed on said shaft and rotated upon movement of said slide bar, a contact operating member for each contact on said shaft and fixed in predetermined angular positions with respect to said gear so that upon movement of said slide bar from one extreme position to the other extreme position to rotate said shaft said operating members will close the first of said contact and open the second of said contacts when said slide bar is in one extreme position and close the second of said contacts and open the first of said contacts when said slide bar is in its other extreme position; a point detector mechanism connected to said switch points, a third contact operating member rotatable on said shaft and operatively connected to said point detector mechanism so that when said point detector mechanism is operated by a displaced switch point said third contact operating member will be rotated to open the closed contact, a pivoted latch member overlying said gear and biased toward a latching position, said latch member rotating to its latching position when said third contact operating member is rotated by said point detector mechanism to hold said member in its contact opening position, and a cam on said gear for moving said latch member to its unlatching position to release said third contact operating member when said slide bar is moved from one extreme position toward its other extreme position.

HERBERT L. BONE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,053,891 Bcall Sept. 8, 1936 2,067,974 McWhirter'et a1. Jan. 19, 1937 2,124,739 Kershaw July 26, 1938 2,388,819 Bone Nov. 13, 1945 

